In the construction industry which uses heavy rolling equipment, the time, expense and loss of production resulting from punctured pneumatic tires or "flats" can be substantial. In some instances, standard pneumatic tires have been filled with fluid rubber, elastomeric or a urethane foam material which solidifies in the tire to avoid flats and the down time associated with repairing and reinflating the tires. This has not been found to be totally satisfactory because the standard pneumatic tires have a very large capacity for such elastomeric foam or solidifying rubber so that the weight of such tires is substantially increased thereby reducing the usable power of the heavy equipment as well as substantially increasing wear and tear on the equipment.
In the past, solid rubber has been used on some types of rolling equipment having low torque requirements or small diameter tires, such as trucks or forklifts. Solid rubber tires for larger equipment have not been acceptable because of the large rotational weight resulting from very massive solid rubber tires. Also, means for preventing slippage of the tires with respect to the rims in high torque applications has proved to be inadequate for heavy construction equipment. While such prior solid rubber tires for a forklift used in a smooth cement floor wearhouse environment may be satisfactory, it is unacceptable in rough terrain high torque situations.
Solid rubber tires of the type depicted in Smith U.S. Pat. No. 2,896,687 have been devised in which an extruded resilient rubber cushion core is encased in a correspondingly formed extrusion of abrasion-resistant stock rubber. Smith teaches encasing a metal band between a base strip of hard rubber and the extruded resilient rubber and abrasion resistant stock. The entire assembly is vulcanized to provide surface to surface binding. The purpose of the metal band is to provide adequate tension between oppositely angled, separable tapered flanges of the wheel rim. When the two halves of the wheel are fastened together, the tapered flanges force the base layer outwardly against the metal band to provide tension between the tire and the wheel surface in an attempt to reduce slippage between the tire and rim. This construction has not been found to be totally satisfactory for several reasons, including the expense of extruding various sizes and shapes of resilient core material and correspondingly shaped abrasion resistant exterior stock material. Further, mere radial tension created between the wheel tapered flange portions and the base strip which is backed up by a metal band is not adequate to avoid slippage in many high torque installations. Further, without observance of close tolerances, the tension may be too great or too little when the halves of the wheel are fully tightened. Further, the vulcanization process does not always result in adequate attachment or bonding between the internal metal band and the various rubber extrusions.